Input: unified force feedback support for memoryless devices
[linux-2.6.git] / drivers / input / ff-memless.c
1 /*
2  *  Force feedback support for memoryless devices
3  *
4  *  Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
5  *  Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
6  */
7
8 /*
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23
24 /* #define DEBUG */
25
26 #define debug(format, arg...) pr_debug("ff-memless: " format "\n", ## arg)
27
28 #include <linux/input.h>
29 #include <linux/module.h>
30 #include <linux/mutex.h>
31 #include <linux/spinlock.h>
32 #include <linux/sched.h>
33
34 #include "fixp-arith.h"
35
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>");
38 MODULE_DESCRIPTION("Force feedback support for memoryless devices");
39
40 /* Number of effects handled with memoryless devices */
41 #define FF_MEMLESS_EFFECTS      16
42
43 /* Envelope update interval in ms */
44 #define FF_ENVELOPE_INTERVAL    50
45
46 #define FF_EFFECT_STARTED       0
47 #define FF_EFFECT_PLAYING       1
48 #define FF_EFFECT_ABORTING      2
49
50 struct ml_effect_state {
51         struct ff_effect *effect;
52         unsigned long flags;    /* effect state (STARTED, PLAYING, etc) */
53         int count;              /* loop count of the effect */
54         unsigned long play_at;  /* start time */
55         unsigned long stop_at;  /* stop time */
56         unsigned long adj_at;   /* last time the effect was sent */
57 };
58
59 struct ml_device {
60         void *private;
61         struct ml_effect_state states[FF_MEMLESS_EFFECTS];
62         int gain;
63         struct timer_list timer;
64         spinlock_t timer_lock;
65         struct input_dev *dev;
66
67         int (*play_effect)(struct input_dev *dev, void *data,
68                            struct ff_effect *effect);
69 };
70
71 static const struct ff_envelope *get_envelope(const struct ff_effect *effect)
72 {
73         static const struct ff_envelope empty_envelope;
74
75         switch (effect->type) {
76                 case FF_PERIODIC:
77                         return &effect->u.periodic.envelope;
78                 case FF_CONSTANT:
79                         return &effect->u.constant.envelope;
80                 default:
81                         return &empty_envelope;
82         }
83 }
84
85 /*
86  * Check for the next time envelope requires an update on memoryless devices
87  */
88 static unsigned long calculate_next_time(struct ml_effect_state *state)
89 {
90         const struct ff_envelope *envelope = get_envelope(state->effect);
91         unsigned long attack_stop, fade_start, next_fade;
92
93         if (envelope->attack_length) {
94                 attack_stop = state->play_at +
95                         msecs_to_jiffies(envelope->attack_length);
96                 if (time_before(state->adj_at, attack_stop))
97                         return state->adj_at +
98                                         msecs_to_jiffies(FF_ENVELOPE_INTERVAL);
99         }
100
101         if (state->effect->replay.length) {
102                 if (envelope->fade_length) {
103                         /* check when fading should start */
104                         fade_start = state->stop_at -
105                                         msecs_to_jiffies(envelope->fade_length);
106
107                         if (time_before(state->adj_at, fade_start))
108                                 return fade_start;
109
110                         /* already fading, advance to next checkpoint */
111                         next_fade = state->adj_at +
112                                         msecs_to_jiffies(FF_ENVELOPE_INTERVAL);
113                         if (time_before(next_fade, state->stop_at))
114                                 return next_fade;
115                 }
116
117                 return state->stop_at;
118         }
119
120         return state->play_at;
121 }
122
123 static void ml_schedule_timer(struct ml_device *ml)
124 {
125         struct ml_effect_state *state;
126         unsigned long now = jiffies;
127         unsigned long earliest = 0;
128         unsigned long next_at;
129         int events = 0;
130         int i;
131
132         debug("calculating next timer");
133
134         for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
135
136                 state = &ml->states[i];
137
138                 if (!test_bit(FF_EFFECT_STARTED, &state->flags))
139                         continue;
140
141                 if (test_bit(FF_EFFECT_PLAYING, &state->flags))
142                         next_at = calculate_next_time(state);
143                 else
144                         next_at = state->play_at;
145
146                 if (time_before_eq(now, next_at) &&
147                     (++events == 1 || time_before(next_at, earliest)))
148                         earliest = next_at;
149         }
150
151         if (!events) {
152                 debug("no actions");
153                 del_timer(&ml->timer);
154         } else {
155                 debug("timer set");
156                 mod_timer(&ml->timer, earliest);
157         }
158 }
159
160 /*
161  * Apply an envelope to a value
162  */
163 static int apply_envelope(struct ml_effect_state *state, int value,
164                           struct ff_envelope *envelope)
165 {
166         struct ff_effect *effect = state->effect;
167         unsigned long now = jiffies;
168         int time_from_level;
169         int time_of_envelope;
170         int envelope_level;
171         int difference;
172
173         if (envelope->attack_length &&
174             time_before(now,
175                         state->play_at + msecs_to_jiffies(envelope->attack_length))) {
176                 debug("value = 0x%x, attack_level = 0x%x", value,
177                       envelope->attack_level);
178                 time_from_level = jiffies_to_msecs(now - state->play_at);
179                 time_of_envelope = envelope->attack_length;
180                 envelope_level = min_t(__s16, envelope->attack_level, 0x7fff);
181
182         } else if (envelope->fade_length && effect->replay.length &&
183                    time_after(now,
184                               state->stop_at - msecs_to_jiffies(envelope->fade_length)) &&
185                    time_before(now, state->stop_at)) {
186                 time_from_level = jiffies_to_msecs(state->stop_at - now);
187                 time_of_envelope = envelope->fade_length;
188                 envelope_level = min_t(__s16, envelope->fade_level, 0x7fff);
189         } else
190                 return value;
191
192         difference = abs(value) - envelope_level;
193
194         debug("difference = %d", difference);
195         debug("time_from_level = 0x%x", time_from_level);
196         debug("time_of_envelope = 0x%x", time_of_envelope);
197
198         difference = difference * time_from_level / time_of_envelope;
199
200         debug("difference = %d", difference);
201
202         return value < 0 ?
203                 -(difference + envelope_level) : (difference + envelope_level);
204 }
205
206 /*
207  * Return the type the effect has to be converted into (memless devices)
208  */
209 static int get_compatible_type(struct ff_device *ff, int effect_type)
210 {
211
212         if (test_bit(effect_type, ff->ffbit))
213                 return effect_type;
214
215         if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit))
216                 return FF_RUMBLE;
217
218         printk(KERN_ERR
219                "ff-memless: invalid type in get_compatible_type()\n");
220
221         return 0;
222 }
223
224 /*
225  * Combine two effects and apply gain.
226  */
227 static void ml_combine_effects(struct ff_effect *effect,
228                                struct ml_effect_state *state,
229                                int gain)
230 {
231         struct ff_effect *new = state->effect;
232         unsigned int strong, weak, i;
233         int x, y;
234         fixp_t level;
235
236         switch (new->type) {
237         case FF_CONSTANT:
238                 i = new->direction * 360 / 0xffff;
239                 level = fixp_new16(apply_envelope(state,
240                                         new->u.constant.level,
241                                         &new->u.constant.envelope));
242                 x = fixp_mult(fixp_sin(i), level) * gain / 0xffff;
243                 y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff;
244                 /*
245                  * here we abuse ff_ramp to hold x and y of constant force
246                  * If in future any driver wants something else than x and y
247                  * in s8, this should be changed to something more generic
248                  */
249                 effect->u.ramp.start_level =
250                         max(min(effect->u.ramp.start_level + x, 0x7f), -0x80);
251                 effect->u.ramp.end_level =
252                         max(min(effect->u.ramp.end_level + y, 0x7f), -0x80);
253                 break;
254
255         case FF_RUMBLE:
256                 strong = new->u.rumble.strong_magnitude * gain / 0xffff;
257                 weak = new->u.rumble.weak_magnitude * gain / 0xffff;
258                 effect->u.rumble.strong_magnitude =
259                         min(strong + effect->u.rumble.strong_magnitude,
260                             0xffffU);
261                 effect->u.rumble.weak_magnitude =
262                         min(weak + effect->u.rumble.weak_magnitude, 0xffffU);
263                 break;
264
265         case FF_PERIODIC:
266                 i = apply_envelope(state, abs(new->u.periodic.magnitude),
267                                    &new->u.periodic.envelope);
268
269                 /* here we also scale it 0x7fff => 0xffff */
270                 i = i * gain / 0x7fff;
271
272                 effect->u.rumble.strong_magnitude =
273                         min(i + effect->u.rumble.strong_magnitude, 0xffffU);
274                 effect->u.rumble.weak_magnitude =
275                         min(i + effect->u.rumble.weak_magnitude, 0xffffU);
276                 break;
277
278         default:
279                 printk(KERN_ERR "ff-memless: invalid type in ml_combine_effects()\n");
280                 break;
281         }
282
283 }
284
285
286 /*
287  * Because memoryless devices have only one effect per effect type active
288  * at one time we have to combine multiple effects into one
289  */
290 static int ml_get_combo_effect(struct ml_device *ml,
291                                unsigned long *effect_handled,
292                                struct ff_effect *combo_effect)
293 {
294         struct ff_effect *effect;
295         struct ml_effect_state *state;
296         int effect_type;
297         int i;
298
299         memset(combo_effect, 0, sizeof(struct ff_effect));
300
301         for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
302                 if (__test_and_set_bit(i, effect_handled))
303                         continue;
304
305                 state = &ml->states[i];
306                 effect = state->effect;
307
308                 if (!test_bit(FF_EFFECT_STARTED, &state->flags))
309                         continue;
310
311                 if (time_before(jiffies, state->play_at))
312                         continue;
313
314                 /*
315                  * here we have started effects that are either
316                  * currently playing (and may need be aborted)
317                  * or need to start playing.
318                  */
319                 effect_type = get_compatible_type(ml->dev->ff, effect->type);
320                 if (combo_effect->type != effect_type) {
321                         if (combo_effect->type != 0) {
322                                 __clear_bit(i, effect_handled);
323                                 continue;
324                         }
325                         combo_effect->type = effect_type;
326                 }
327
328                 if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) {
329                         __clear_bit(FF_EFFECT_PLAYING, &state->flags);
330                         __clear_bit(FF_EFFECT_STARTED, &state->flags);
331                 } else if (effect->replay.length &&
332                            time_after_eq(jiffies, state->stop_at)) {
333
334                         __clear_bit(FF_EFFECT_PLAYING, &state->flags);
335
336                         if (--state->count <= 0) {
337                                 __clear_bit(FF_EFFECT_STARTED, &state->flags);
338                         } else {
339                                 state->play_at = jiffies +
340                                         msecs_to_jiffies(effect->replay.delay);
341                                 state->stop_at = state->play_at +
342                                         msecs_to_jiffies(effect->replay.length);
343                         }
344                 } else {
345                         __set_bit(FF_EFFECT_PLAYING, &state->flags);
346                         state->adj_at = jiffies;
347                         ml_combine_effects(combo_effect, state, ml->gain);
348                 }
349         }
350
351         return combo_effect->type != 0;
352 }
353
354 static void ml_play_effects(struct ml_device *ml)
355 {
356         struct ff_effect effect;
357         DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS);
358
359         memset(handled_bm, 0, sizeof(handled_bm));
360
361         while (ml_get_combo_effect(ml, handled_bm, &effect))
362                 ml->play_effect(ml->dev, ml->private, &effect);
363
364         ml_schedule_timer(ml);
365 }
366
367 static void ml_effect_timer(unsigned long timer_data)
368 {
369         struct input_dev *dev = (struct input_dev *)timer_data;
370         struct ml_device *ml = dev->ff->private;
371
372         debug("timer: updating effects");
373
374         spin_lock(&ml->timer_lock);
375         ml_play_effects(ml);
376         spin_unlock(&ml->timer_lock);
377 }
378
379 static void ml_ff_set_gain(struct input_dev *dev, u16 gain)
380 {
381         struct ml_device *ml = dev->ff->private;
382         int i;
383
384         spin_lock_bh(&ml->timer_lock);
385
386         ml->gain = gain;
387
388         for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
389                 __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags);
390
391         ml_play_effects(ml);
392
393         spin_unlock_bh(&ml->timer_lock);
394 }
395
396 static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
397 {
398         struct ml_device *ml = dev->ff->private;
399         struct ml_effect_state *state = &ml->states[effect_id];
400
401         spin_lock_bh(&ml->timer_lock);
402
403         if (value > 0) {
404                 debug("initiated play");
405
406                 __set_bit(FF_EFFECT_STARTED, &state->flags);
407                 state->count = value;
408                 state->play_at = jiffies +
409                                  msecs_to_jiffies(state->effect->replay.delay);
410                 state->stop_at = state->play_at +
411                                  msecs_to_jiffies(state->effect->replay.length);
412                 state->adj_at = state->play_at;
413
414                 ml_schedule_timer(ml);
415
416         } else {
417                 debug("initiated stop");
418
419                 if (test_bit(FF_EFFECT_PLAYING, &state->flags))
420                         __set_bit(FF_EFFECT_ABORTING, &state->flags);
421                 else
422                         __clear_bit(FF_EFFECT_STARTED, &state->flags);
423
424                 ml_play_effects(ml);
425         }
426
427         spin_unlock_bh(&ml->timer_lock);
428
429         return 0;
430 }
431
432 static int ml_ff_upload(struct input_dev *dev,
433                         struct ff_effect *effect, struct ff_effect *old)
434 {
435         struct ml_device *ml = dev->ff->private;
436         struct ml_effect_state *state = &ml->states[effect->id];
437
438         spin_lock_bh(&ml->timer_lock);
439
440         if (test_bit(FF_EFFECT_STARTED, &state->flags)) {
441                 __clear_bit(FF_EFFECT_PLAYING, &state->flags);
442                 state->play_at = jiffies +
443                                  msecs_to_jiffies(state->effect->replay.delay);
444                 state->stop_at = state->play_at +
445                                  msecs_to_jiffies(state->effect->replay.length);
446                 state->adj_at = state->play_at;
447                 ml_schedule_timer(ml);
448         }
449
450         spin_unlock_bh(&ml->timer_lock);
451
452         return 0;
453 }
454
455 static void ml_ff_destroy(struct ff_device *ff)
456 {
457         struct ml_device *ml = ff->private;
458
459         kfree(ml->private);
460 }
461
462 /**
463  * input_ff_create_memless() - create memoryless FF device
464  * @dev: input device supporting force-feedback
465  * @data: driver-specific data to be passed into @play_effect
466  * @play_effect: driver-specific method for playing FF effect
467  */
468 int input_ff_create_memless(struct input_dev *dev, void *data,
469                 int (*play_effect)(struct input_dev *, void *, struct ff_effect *))
470 {
471         struct ml_device *ml;
472         struct ff_device *ff;
473         int error;
474         int i;
475
476         ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL);
477         if (!ml)
478                 return -ENOMEM;
479
480         ml->dev = dev;
481         ml->private = data;
482         ml->play_effect = play_effect;
483         ml->gain = 0xffff;
484         spin_lock_init(&ml->timer_lock);
485         setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev);
486
487         set_bit(FF_GAIN, dev->ffbit);
488
489         error = input_ff_create(dev, FF_MEMLESS_EFFECTS);
490         if (error) {
491                 kfree(ml);
492                 return error;
493         }
494
495         ff = dev->ff;
496         ff->private = ml;
497         ff->upload = ml_ff_upload;
498         ff->playback = ml_ff_playback;
499         ff->set_gain = ml_ff_set_gain;
500         ff->destroy = ml_ff_destroy;
501
502         /* we can emulate periodic effects with RUMBLE */
503         if (test_bit(FF_RUMBLE, ff->ffbit)) {
504                 set_bit(FF_PERIODIC, dev->ffbit);
505                 set_bit(FF_SINE, dev->ffbit);
506                 set_bit(FF_TRIANGLE, dev->ffbit);
507                 set_bit(FF_SQUARE, dev->ffbit);
508         }
509
510         for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
511                 ml->states[i].effect = &ff->effects[i];
512
513         return 0;
514 }
515 EXPORT_SYMBOL_GPL(input_ff_create_memless);